<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box {
            display:grid;
            width: 400px;
            
            grid-template-columns:200px 100px auto;
            grid-template-rows:repeat(2,100px 100px 100px);
            column-gap:10px;
            row-gap:20px;
            
            
        }
        .item:nth-of-type(2n) {
            background-color: red;
        }
        .item:nth-of-type(2n+1) {
            background-color:greenyellow;
        }
    </style>
</head>
<body>
    <div class="box">
        <div class="item"><h1>1</h1></div>
        <div class="item"><h1>12</h1></div>
        <div class="item"><h1>13</h1></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item" style="width:100px;height:100px;"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        
    </div>
    <div style="width:200px;height:300px;background-color:red;"></div>
</body>
</html>